The present invention relates generally to a radio-frequency identification (RFID) device comprising a printed electronic circuit (PEC). Specifically, the PEC or electronic circuit which includes printed elements is coupled to a conductor structure, such as an antenna, by reactive means, such as an electric field, a magnetic field, or a combination of both. In accordance with embodiments of the present subject matter, the PEC may be an RFID device, but may also be other forms of circuits, such as a sensor and its associated signal processing coupled to a standard chip. Accordingly, the present specification makes specific reference thereto.
The use of radio frequency identification (RFID) to identify one of a plurality of items is well known. Typical RFID tags or integrated circuits include a microprocessor, also known as a microchip, electrically connected to an antenna. Alternatively, the microchip is first attached to a pad having electrical leads that provides a larger attachment or “landing” area. This is typically referred to as a “strap” or “interposer.” The strap is then attached to the antenna. Specifically, interposers include conductive leads or pads that are electrically coupled to the contact pads of the chips for coupling to the antennas.
The microprocessor stores data, which can include identifying data unique to a specific item, which is transmitted to an external receiver (interrogator) for reading by an operator and processing of the item. The microprocessor also modulates a radio frequency (RF) signal that is transmitted via the antenna. The external reader (interrogator) is used to capture the data transmitted by the RFID tag. RFID tags can be attached to or associated with items for inventory control, shipment control, loss prevention, and the like. RFID tags are particularly useful in identifying, tracking and controlling items such as packages, pallets, consumer goods, and other product containers. The location of each item can be tracked and information identifying the owner of the item or specific handling requirements, can be encoded into the chip contained in the RFID tag and later read by a scanning device or reader which is capable of decoding and displaying the information previously encoded on the chip.
Accordingly, RFID tags can be attached to or associated with items entering or within a supply chain or retail environment and the identifying information received can be processed for various reasons in a variety of manners. However, the RFID tag can be subject to many factors which degrade the performance of printed semiconductor materials, such as those created using polyaniline and its derivatives, amorphous silicon, or metal oxides.
The present invention discloses an RFID device comprising a PEC. Specifically, the PEC or electronic circuit which includes printed elements is coupled to a conductor structure, such as an antenna, by reactive means, such as an electric field, a magnetic field, or a combination of both. Use of a coupling mechanism that does not rely on a conductive connection, via a conductive adhesive or other means, allows the PEC to be fully covered with a barrier layer, to stop ingress of such things as moisture, oxygen, etc.